[coreboot] Lenovo X230 + 32GB RAM ?

[Nico Huber]

Hi David,

On 03.09.2018 19:13, David Potocnik wrote:
> Coreboot, or perhaps rule it out completely?

it's impossible, unless you want to heavily mod the mainboard. Ivy
Bridge supports 4 ranks per channel, max 4GiB per rank. SO-DIMMs have
only 2 ranks. So with 2 SO-DIMM slots, there are physical connections
missing to get to 32GiB.

> Information on RAM frequencies is welcome as well:
> 
> I've also heard reports of people running the RAM at 1866Mhz. A newer
> version of the official BIOS reduced the original 1666Mhz, to 1333Mhz. I
> believe there's a mod available that over-rides this:
> http://x220.mcdonnelltech.com/resources/
> 
> 
> How is this currently on Coreboot?

coreboot limits the frequency to whatever the board manufacturer con-
figured the chipset to (using one-time programmable fuses). It can be
configured, however, to ignore the fuses. Then it would use whatever
the RAM supports up to the CPU's limit. This is overclocking so there
is no guarantee that it would work on one X230 sample just because it
works on another. And there is probably no real-world application that
would benefit (2 x DDR3-800 is already quite fast compared to what Ivy
bridge can do with the data).

Hard to tell why Lenovo lowered the frequency late. Maybe because there
was no performance impact but it saves power?

Nico